To readily obtain in a short time a three-dimensional ultrasound diagnosis image of superficial tissues such as mammary gland, thyroid gland, carotid, body surface blood vessel and body surface for example, it is necessary to obtain a wide visual field region of an array type device in a region near the body surface, and to perform wide mechanical scanning along the shape of the body surface in a direction orthogonal to the scan direction of the array type device. In particular, with a hand carry type ultrasound probe, since three-dimensional images of various superficial tissues can be obtained with one three-dimensional ultrasound probe, it is possible to save diagnostic task of replacing probes, and to eliminate the need for using multiple three-dimensional ultrasound probes, which is great advantage in terms of cost. In addition, it is desirable to reduce the size of the shape of a probe as much as possible when the shape and position of diagnosis portions such as carotid thyroid gland are taken into consideration, for example. However, downsizing a three-dimensional ultrasound probe conflicts with increasing the three-dimensional diagnosis region.
Under such circumstances, a hand carry type three-dimensional ultrasound probe is known in which a mechanism that translates an ultrasound device by using a belt is applied to a hand carry type ultrasound probe, for example (see, for example, PTL 1). As illustrated in FIG. 18, the ultrasound probe disclosed in PTL 1 includes, in casing 100, five pulleys 101, timing pulley 102 provided with a flange which includes a toothed part on its outer periphery, belt 103 that surrounds pulleys 101 and 102, guide 104, and ultrasound device 105. Belt 103 reciprocates in direction A and direction B in the drawing when timing pulley 102 rotates, and ultrasound device 105 firmly fixed to belt 103 also reciprocates along guide 104.